Legend
LED — Light-Emitting Diode
SCR — Silicon Control Rectifie r
SMM — Starter Manag ement Module
AK board power
applied, run comman d
given, starter at ful l
voltage, but aux LED
not lit.
AK board not functioning
properly. Replace board.
1L boards LEDs lit. Motor terminal voltage
phase imbalance exists. Check motor terminal voltages for imbalance between
phases. If an imbalance ex ists, check for loose SCR gat e
or open SCR gate. Replace phase assembly, if necessary.
BC board LED L4 and
L5 not lit. BC board not functioning
properly. Replace board.
BC board LED L3 lit. 1. FU5 and FU6 fuses not
functioning properly.
2. Phase assembly not
functioning properly.
3. Fan not functioning
properly.
1. Check fuses FU5 and FU6. R eplace if necessary.
2. Verify that bypass is pul ling in by measuring the voltag e
drop across the contacts . The reading should b e 50 mV
or less. Replace phase asse mbly, if necessary.
3. Verify fan operation on each phase for 200 amp units.
Replace fan, if necessary .
BC board L2 lit. SCR phases not function-
ing properly. Measure r esistance from anode to cat hode for each SCR
phase assembly. Replace sh orted phase, if necess ary.
BC board L1 lit. Motor lead grounded. Megger motor to test f or motor lead going to grou nd.
Start command given. Motor does not begin ro ta-
tion. Turn ‘Starting Torque’ p otentiometer RV2 clockw ise until
motor rotation begins.
Motor does not reach
full speed within 25
seconds.
Ramp up setting is not cor-
rect. Turn ‘Ramp’ potentiomet er RV1 counterclockwise . Restart
motor and verify that mo tor reaches full speed wi thin 25
seconds.
115 vac missing from
LL1 and LL2. 1. CB2 is not on.
2. Fuse no. 4 (FU4) blown. 1. Verify CB2 is on.
2. Check FU4 for continuity. Replace, if necessary.
SMM not responding. 1. CB4 is not on.
2. Potentiometer RV1
needs adjustment.
1. Verify CB4 is on.
2. Adjust potentiometer RV 1 for 24 vac at SMM termina ls
J3-23 and J3-24.
Table 12 — Benshaw, Inc. Solid-State Starter Troubleshooting Guide (Co ntinue d)
Problem Probable Causes Area of Correction